Synthesis And Photochemical Oxidation Desulfurization Aetivity Of BiVO₄under Visible-Light Irradiation

With the enhancement of people’s environmental awareness, The elimination ofsulfur compounds in fuel oil have gradually became the focus of attention, so diversescholars have actively explored the new and potential desulfurization technology.Photocatalytic oxidative desulfurization as develops into the most promisingdesulfurization technology, because of many advantages, such as, reaction condition ismild, technology is easy and desulfurization result is high. And the core of this skill is tosynthetize the photocatalyst which can be driven by visible light. In this research, usingthe elimination of characteristic sulfur compound—thiophene to be study object, wedesigned and synthetized the new-type BiVO₄photocatalyst, which shows differentshape and can be responsen by visible light. In this work such points were investigatedsystemicly:1. Taking temperature, precursor pH, reaction time as discussing objects, the effect ofhydrothermal reaction conditions on the component, morphology, light absorption andadsorption properties of BiVO₄photocatalyst were researched. The as-prepared sampleswere characterized by XRD, UV-vis DRS, SEM and BET.2. In the experiment of desulfurization of model oil, using BiVO₄synthetized byhydrothermal method as photocatalyst, using O2as oxidantand metal halide as visiblelight source, the impacts of different operating conditions （illumination time, catalystamount, air flow） on photocatalytic activities were investigated. Furthermore, ResponseSurface Methodology was used to optimize the experiment. The results showed thatunder the optimal conditions（1.0mg/mL of catalyst,200ml/min of air,2.5h ofillumination time）, the sulfur content could be reduced to70μg/g from500μg/g, and thedesulfurization rate were86%above, which have reached the national standard. 3. Via setting up the dynamic model of desulfurization of model oil, thephotocatalytic desulfurization reaction could be described by an apparent first-orderreaction by differential method, and caculated by the fitting Linear equations, the rateconstants K is0.5505min-1（under the optimal technological conditions）.4. In order to effectually restrain the combination of photogenerated electro-holeand improve the photocatalytic properties, the metal was doped into monoclinic scheeliteBiVO₄synthetized by hydrothermal method. And the impacts of synthetized factors onphyical structures were investigated, meanwhile, the influence of reaction conditions ondesulfurization rate were disscussed as well.This work can be used as the reference for the controllable synthesis and modifyingstudy of BiVO₄photocatalyst. In addition, it supplied reliably theoretical reference valuefor the practical application of BiVO₄photocatalyst.